subtle summit
Often considered relatively mid vouchers, I think it would be cool if the cards provided would lean towards synergizing with your deck or build.
When picking cards to show up in the store, it would have a preference to providing cards that work with Jokers you have.
For example: if you have Baron, it would have an increased chance of showing Kings. Or, if you had Odd Todd, it would have an increased chance of showing odd cards. If you have multiple of these jokers, it would randomly pick between one of them.
Additionally, it could take into consideration what your deck is made of.
For example: if you have more Aces than any other card, it would have a higher chance to show aces. If you have Aces and Nines at the same amount, it would pick one randomly.
Maybe a 1/3 chance to show a random card, 1/3 chance to show a card that works with a joker you have, and 1/3 chance to show a card that matches the highest quantity card in your deck.
Though, assuming it doesn't become broken, I could also see it being priority based. If you have a joker that cares about specific cards or card qualities it only shows cards that fit that bill. If not, it shows cards that match rank with your highest rank or suit with your highest suit. If suits and ranks are the same, then it's random.